This is an improvement upon the invention of U.S. Pat. No. 5,113,746 and relates to a guided cylinder wherein improved abutment means are provided for connecting the guide rods to the yoke.
Guide cylinders have been provided by positioning a pair of diagonally opposed guide rods upon a vertically slidable mounting in the cylinder and bridging the guide rods by means of a yoke. A piston rod is connected to the yoke between the guide rods on one end and to a piston on the other end. It is also the common practice to utilize guide rods of uniform cross section throughout their length and to provide an internal bore at an upper end to facilitate attachment of the yoke thereto. The inward movement of the piston rod and the yoke attached to the upper end thereto between the guide rods toward the cylinder is limited by means of an end cap or some other internal structure which normally does not permit the yoke to come into sufficiently close contact with the cylinder as may result in injury to a finger inadvertently placed between the yoke and the cylinder. Such cylinders are intended for use with both torsional and direct side loading.
By means of the guide rods, the turning of the piston and the rod attached thereto is avoided, and positive guidance is provided thereby averting damage to the cylinder walls and associated parts. By limiting the rotation of the piston rod, it is thus possible to limit the length of the piston (since less guidance would require greater length) to thereby aid in the provision of miniature cylinders.
Accordingly, it is an important object of the invention to provide a guide cylinder wherein a firm support is provided for attaching the guide rods to the yokes by providing abutment means affording bearing surfaces in contact with the yokes and recesses in the yokes for receiving integral abutments extending therein to avoid substantial lateral movement as may permit misalignment of the guide rods in the cylinder.
Another important object of the invention is provided by guide rods having flats positioned on upper ends thereto adjacent the yoke to provide means for gripping same when inserting and tightening the screws attaching the yoke to the guide rods.
Still another important object of the invention is to avoid the trapping of a finger between the yoke and the cylinder as may cause injury thereto.